In Xiaohua Mall's own words, what role does his beard play in this article?

The book says that it uses its beard to test the size of the hole, that is, if the beard doesn't touch the edge of the hole, it can safely get in. If the beard touches it, it may get stuck in it again.

But I really see that my cat doesn't need a beard to do anything. It just uses its head to squeeze, as long as its head can squeeze through its body.

It used to want to burn its beard because it smelled a candle (at first it didn't know what the flame of the candle was, so it jumped strangely), but it hasn't seen what it looked like since. It runs and jumps as before, catching mice. Later, the burnt beard grew back.

I think its beard is equivalent to touch. For example, people always want to touch something to see what it is, so the cat touches it with its beard and smells it with its nose.